The present invention relates to an optical cable comprising one or more optical waveguides, wherein the one or more optical waveguides are provided with a protective layer, a buffer tube surrounding the one or more optical waveguides, wherein the buffer tube is surrounded by an outer sheath, and while a radial interspace is present between the outer sheath and the buffer tube, and wherein the radial interspace is filled with a filler.
Such a cable is known per se from British patent application GB 2 215 480, in which six buffer tubes are arranged around a central strengthening element, with the buffer tubes in turn being surrounded by an outer sheath. Each buffer tube contains six optical fibres, wherein the fibres are provided with a coating, and while the interspace between the coated optical fibres and the inner side of the buffer tube is filled with a filler. A thermoplastic polyester, in particular Hytrel, is used as a suitable material for the aforesaid buffer tube.
The present inventors are active in the field of so-called “direct buried drop cables”, wherein these cables are placed underground for use in so-called “fibre to the home” (FTTH) networks, in which optical fibre cables are laid to homes. In a construction of this kind, optical fibres from different cables need to be connected together, with the weld housings usually being placed in the ground. The welding of optical fibres takes place aboveground, however, and some excess length of the optical fibres is needed for carrying out such welding operations. The optical fibre is frequently subject to mechanical loads, such as bending, during such operations. Said mechanical loads may cause the optical properties of the fibre to deteriorate.